molstar
Version:
A comprehensive macromolecular library.
62 lines (61 loc) • 2.31 kB
JavaScript
;
/**
* Copyright (c) 2018 mol* contributors, licensed under MIT, See LICENSE file for more info.
*
* @author Alexander Rose <alexander.rose@weirdbyte.de>
*/
Object.defineProperty(exports, "__esModule", { value: true });
exports.setCanvasSize = setCanvasSize;
exports.resizeCanvas = resizeCanvas;
exports.canvasToBlob = canvasToBlob;
/** Set canvas size taking `devicePixelRatio` into account */
function setCanvasSize(canvas, width, height, scale = 1) {
canvas.width = Math.round(window.devicePixelRatio * scale * width);
canvas.height = Math.round(window.devicePixelRatio * scale * height);
Object.assign(canvas.style, { width: `${width}px`, height: `${height}px` });
}
/** Resize canvas to container element taking `devicePixelRatio` into account */
function resizeCanvas(canvas, container, scale = 1) {
let width = window.innerWidth;
let height = window.innerHeight;
if (container !== document.body) {
// fixes issue #molstar/molstar#147, offsetWidth/offsetHeight is correct size when css transform:scale is used
width = container.offsetWidth;
height = container.offsetHeight;
}
setCanvasSize(canvas, width, height, scale);
}
function _canvasToBlob(canvas, callback, type, quality) {
const bin = atob(canvas.toDataURL(type, quality).split(',')[1]);
const len = bin.length;
const len32 = len >> 2;
const a8 = new Uint8Array(len);
const a32 = new Uint32Array(a8.buffer, 0, len32);
let j = 0;
for (let i = 0; i < len32; ++i) {
a32[i] = bin.charCodeAt(j++) |
bin.charCodeAt(j++) << 8 |
bin.charCodeAt(j++) << 16 |
bin.charCodeAt(j++) << 24;
}
let tailLength = len & 3;
while (tailLength--)
a8[j] = bin.charCodeAt(j++);
callback(new Blob([a8], { type: type || 'image/png' }));
}
async function canvasToBlob(canvas, type, quality) {
return new Promise((resolve, reject) => {
const callback = (blob) => {
if (blob)
resolve(blob);
else
reject('no blob returned');
};
if (!HTMLCanvasElement.prototype.toBlob) {
_canvasToBlob(canvas, callback, type, quality);
}
else {
canvas.toBlob(callback, type, quality);
}
});
}